Energy absorbing tether clip

ABSTRACT

A releasable fastener includes a tether and a clip adapted to be coupled to a first member. The tether has a first end releasably coupled to the clip, a second end adapted to be coupled to a second member that is moveable relative to the first member and a flexible member having first and second strands interconnecting the first and second ends of the tether. The second strand is frangible.

FIELD

The present disclosure relates in general to clip type fasteners andmore specifically to a device and method for creating and using a cliptype fastener assembly to join automobile vehicle component parts.

BACKGROUND

A variety of fasteners have been used within automotive applications tojoin trim pieces to other portions of the automobile. Sometimes thesefasteners are required to be insertable into apertures of the automobileand meet requirements to both retain the trim piece and allow the trimpiece to be later removed if replacement is desired. For example, in theevent that an air bag has been deployed, replacement of the air bagand/or the trim piece supporting the air bag is typically required. Toreplace the trim piece, the fasteners attaching the trim piece to theautomobile also need to be removable. Unfortunately, many availablefasteners do not provide an easily accessible fastener joint to allowremoval of the fastener/trim piece following damage or an air bagdeployment event.

Many vehicles are currently equipped with numerous airbags or aircurtains. Based on the variety of sizes of airbags being installed, anumber of special fasteners have been created to retain the trim pieceenclosing the escape aperture of the airbag. Furthermore, the use ofside curtain airbags has further increased the range of thicknesses ofthe packed airbags currently manufactured.

Other concerns relate to excessive trim piece movement during or afterair curtain deployment. In particular, it may be desirable to restrictthe trim piece from moving once the air curtain has been fully deployed.Accordingly, there may be a need for a single solution fastener for usewith a number of airbag designs having various thicknesses and escapeaperture size requirements. In addition, it may be beneficial to providea compact tethered design for packaging while providing a relativelylong tether length during airbag deployment.

SUMMARY

A releasable fastener includes a tether and a clip adapted to be coupledto a first member. The tether has a first end releasably coupled to theclip, a second end adapted to be coupled to a second member that ismoveable relative to the first member and a flexible member having firstand second strands interconnecting the first and second ends of thetether. The second strand is frangible.

In addition, the present disclosure relates to a releasable fastenerincluding a first connector having a male pin, a second connectorflexibly tethered to the first connector and a clip releasablyengageable with the second connector. The second connector has areceptacle and at least one biasing element operable to releasablyengage the male pin. The flexible tether includes first and secondstrands where each strand has one end proximate to the first connectorand an opposite end proximate to the second connector. The second strandis separable under a tensile load. The first strand continues tointerconnect the first and second connectors when subject to the tensileload.

Further areas of applicability will become apparent from the descriptionprovided herein. It should be understood that the description andspecific examples are intended for purposes of illustration only and arenot intended to limit the scope of the present disclosure.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure will become more fully understood from thedetailed description and the accompanying drawings, wherein:

FIG. 1 is a perspective view of an assembled tethered fastener accordingto the present disclosure;

FIG. 2 is a perspective view of a tether of the fastener of FIG. 1;

FIG. 3 is another perspective view of the tether of the fastener of FIG.1;

FIG. 4 is a perspective view of a clip portion of the fastener of FIG.1;

FIG. 5 is a side elevational view of an assembled fastener of thepresent disclosure;

FIG. 6 is a perspective view of a doghouse portion of an automotivecomponent; and

FIG. 7 is a side view of another tether of a fastener.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The following description is merely exemplary in nature and is in no wayintended to limit the invention, its application, or uses.

Referring to FIGS. 1-4, a connecting tethered fastener assembly 10includes a tether 12 and a clip 14. Clip 14 is coupled to a vehiclepanel 16. Tether 12 includes a first end 18 coupled to a moveablecomponent 20 of the vehicle such as a trim piece associated with air bagdeployment. A second end 22 of tether 12 is coupled to clip 14. Aflexible element 24 interconnects first end 18 and second end 22.

Second end 22 of flexible element 24 includes a substantially U-shapedconnector 30 including a first planar portion 32 and a second planarportion 34. First and second planar portions 32 and 34 are arrangedsubstantially parallel to each other and define a partial slot 36 and asolid section 38 between first planar portion 32 and second planarportion 34. A freely extending end of second planar portion 34 providesa hooked end 40 having a partial cavity 42 and a rounded leading edge44. Partial cavity 42 includes stop face 45. A pin 46 defines alongitudinal axis “Y” which is oriented substantially perpendicular to aplane defined by a face 48 of first planar portion 32. Pin 46 is sizedto be slidably received within an aperture 50 created in clip 14.

Pin 46 includes a bulbous head 64 having a head diameter “A”. Head 64 isconnected by a taper portion 66 to a stem 68. Stem 68 includes a stemdiameter “C” which is smaller than head diameter “A”. Head diameter “A”of pin 46 is sized to clear aperture 50 formed in clip 14. Head diameter“A” of pin 46 is further sized to releasably engage within a steppedreceptacle 70 formed in an engagement member 69 formed at first end 18.Stepped receptacle 70 includes a plurality of stepped deflecting members72 separated from one another by a plurality of channels 74. Eachstepped deflecting member 72 includes a beveled contact surface 76 andan engagement surface 78. Head 64 of pin 46 elastically deflects eachstepped deflecting member 72 as head 64 is inserted into steppedreceptacle 70. When head 64 extends beyond engagement surfaces 78, theelastic bias force of stepped deflecting members 72 direct engagementsurfaces 78 into contact with taper portion 66 of stem 68 to releasablyengage connector 30 to engagement member 69 through clip 14.

Engagement member 69 includes a shoulder 79 at a first end having eachof a first post 80 and a second post 82 transversely extending beyondeach of a pair of side walls 84. A post clearance width “D” is sized toreceive a width of first planar portion 32 of connector 30. First andsecond posts 80,82 provide an anti-rotational feature to preventconnector 30 from rotating with respect to engagement member 69 when pin46 is received within stepped receptacle 70. Engagement member 69 alsoprovides a substantially flat engagement section 86 and a deflectabletab 88.

Clip 14 engages shoulder 79 of engagement member 69. Clip 14 furtherincludes a mounting plate 92 through which an aperture 94 is formed.Mounting plate 92 integrally includes each of a first contact side 96and a second contact side 98. First and second contact sides 96 and 98extend substantially transverse to mounting plate 92. First contact side96 and second contact side 98 of clip 14 extend generally transverselyfrom mounting plate 92. First contact side 96 includes a first exteriorframe section 100, a second exterior frame section 102, and at least onefirst deflectable wing 104 integrally connectable to a cross member 106distally extending from mounting plate 92. Cross member 106 is coupledto a cross member 108 of second contact side 98 by a first retaining tab110 integrally formed with cross member 106 and a second retaining tab112 integrally formed with cross member 108. Each of first retaining tab110 and second retaining tab 112 are deformed such that they interlockas shown with the opposed cross member 106 or 108.

First exterior frame section 100 is integrally connected to mountingplate 92 by a first side wall 114. Similarly, second exterior framesection 102 is integrally connected to mounting plate 92 by a secondside wall 116. First side wall 114 and second side wall 116 each opposea third side wall 118 integrally connected to second contact side 98. Areceiving channel 120 is defined between first side wall 114, secondside wall 116, and third side wall 118. Receiving channel 120 isconfigured to slidably receive engagement member 69 when assembled.Second contact side 98 further includes a first interior frame section122 and a second interior frame section 124 which are similar to firstexterior frame section 100 and second exterior frame section 102. Secondcontact side 98 also includes at least two deflectable wings which arepositioned opposite to first deflectable wing 104, including a seconddeflectable wing 126 and a third deflectable wing 128.

As best seen in FIG. 5, each of the main component parts of fastenerassembly 10 of the present invention are shown in an assembledcondition. Clip 14 is slidably engaged with engagement member 69. Morespecifically, deflectable tab 88 deflects to receive clip 14. Connector30 is rotated such that pin 46 engages stepped receptacle 70. Pin 46 isinsertable into both aperture 50 of clip 14 and stepped receptacle 70.Clip 14 positioned between first and second posts 80,82 and deflectabletab 88.

After fastener assembly 10 is assembled, each of first contact side 96and second contact side 98 of clip 14 are slidably inserted into anaperture 130 formed within vehicle panel 16. Each of first deflectablewing 104, second deflectable wing 126 and third deflectable wing 128deflect upon insertion into aperture 130 and elastically return to anon-deflected or expanded state following insertion. First deflectablewing 104, second deflectable wing 126, and third deflectable wing 128engage a first surface 132 of panel 16, while a plurality of plateengagement members 134 engage an opposed or second surface 136 of panel16.

FIG. 6 depicts a rectangular shaped doghouse 138 includes a flat face140 having an aperture 142 adapted to receive hooked end 40 of connector30. Doghouse 138 is coupled to component 20. Hooked end 40 is positionedoutside of doghouse 138 and positively engages flat face 140 to resistseparation from doghouse 138 unless hooked end 40 is deflected in adirection “E”. Solid section 38 is positioned within a detent 144 formedwithin a wall 146 of doghouse 138. When hooked end 40 is positioned asshown, stop face 45 and solid section 38 each resist translation ofdoghouse 138 relative to connector 30. Hooked end 40 in engagement withdoghouse 138 defines another releasable joint of fastener assembly 10.

Four primary releasable connections are formed when using fastenerassembly 10 to join component 20 to panel 16 of a vehicle. Thereleasable connections define a sequential or ascending order of jointintegral strength. A first releasable connection 145 is formed betweenpin 46 and stepped receptacle 70. A second releasable connection 147 isformed between hooked end 40 and aperture 142 of doghouse 138. Secondreleasable connection 147 physically joins doghouse 138 to connector 30.This releasable connection is designed to release within a sequentialorder after first releasable connection 145 to allow repair orreplacement of the trim panel. A third releasable connection 148 isformed between clip 14 and engagement member 69. A fourth releasableconnection 149 is formed by contact between first deflectable wing 104,second deflectable wing 126, and third deflectable wing 128 of clip 14and panel 16. The retention strength of each of the releasableconnections increases from first releasable connection 145 to the fourthreleasable connection 149, wherein each successive releasable connectionforms a stronger joint than the joint(s) preceding it. In other words,the first releasable connection intended to disengage or be disengagedin use is first releasable connection 145. One purpose for providingindividual joining strengths for each of the releasable connections ofthe present invention is to allow, for example, a component part such asa trim panel to separate from a body panel of a vehicle in the eventthat an air bag associated with the trim panel deploys. By designingfirst releasable connection 145 to separate first, flexible element 24will continue to retain component 20 via doghouse 138 to panel 16.

During airbag deployment, and after first releasable connection hasreleased, frangible strands of flexible element 24 separate to allowproper airbag deployment. Flexible element 24 includes a main strand 150interconnecting connector 30 and engagement member 69. A second strand152 is positioned in parallel with main strand 150 and alsointerconnects connector 30 with engagement member 69. Main strand 150 islonger than secondary strand 152. In addition, main strand 150 may havea thickness 154 greater than a nominal thickness 156 of secondary strand152. Sections 158 of secondary strand 152 may have a further reducedthickness than section 156.

Upon airbag deployment, first releasable connection 145 is disconnectedwhere pin 46 is released from engagement with stepped receptacle 70.Flexible member 24 begins to extend as the airbag continues to deploy.As flexible member 24 extends, secondary strand 152 becomes taut andsubsequently separates at one of reduced thickness sections 158.Secondary strand 152 separates allowing the extended length of flexibleelement 24 to increase and allow an opening (not shown) for the airbagto pass through to become larger. Once the widest portion of the stilldeploying airbag passes through the opening, the airbag no longerapplies a force to the component 20. However, component 20 continues tomove with its own momentum being a function of its mass and velocity. Atthis time, main strand 150 begins to arrest the momentum of component20. Main strand 150 maintains an interconnection between connector 30and engagement member 69.

FIG. 7 depicts another tether 200 including a flexible element 201.Tether 200 is substantially similar to tether 12. Accordingly, likeelements will be identified with similar reference numerals having aprime suffix. Tether 200 includes a third strand 202 and a fourth strand204 in addition to main strand 150′ and secondary strand 152′. Inflexible element 201, fourth strand 204 is the shortest of all strands.Third strand 202 is the next longest strand while secondary strand 152′is second longest, shorter only than main strand 150′. By arranging thestrands in this manner, tensile loading between first end 18 and secondend 22 will be sequentially placed across fourth strand 204, thirdstrand 202, secondary strand 152 and lastly main strand 150. One or morestrands may separate depending on the mass of the movable component 20and the impulse of force onto component 20 from the airbag as itdeploys. Each of the strands 150′, 152′, 202 and 204 may be formed toinclude different thicknesses or widths as well. Strands 152′, 202 and204 may also include localized reduced section thicknesses similar toportions 158 formed on secondary strand 152. Each of the variances instructure between the strands causes each strand to separate at adifferent tensile force.

An alternative way to accomplish strand separation at various tensileforces includes molding the strands from different materials. Amulti-shot injection mold may be utilized to construct one or more ofthe strands from a first material and the remaining portions of flexibleelements 24 or 201 from another plastic material.

Based on the use of main strand 150 and secondary strand 152, tether 12may be constructed as a relatively compact folded member useful with anumber of airbags of various thickness. More specifically, if arelatively small airbag is to be deployed, only fourth strand 204 willseparate during deployment while the remaining strands restrict themovement of component 20 relative to the vehicle. If a relatively largeairbag, such as a side air curtain is deployed, each of secondary strand152′, third strand 202 and fourth strand 204 may separate to increasethe size of the opening through which the side air curtain travels. Mainstrand 150′ remains intact to arrest the motion of component 20 afterthe side curtain has been deployed. Based on the above description, oneskilled in the art will appreciate that part proliferation of flexibleelement 24 and flexible element 201 may be greatly reduced becausefastener assembly 10 may be fitted with a common tether for a variety ofairbag applications.

After airbag deployment has completed and at least strand 150 arrestsmovement of component 20, second releasable connection 147 is designedto be released to allow complete separation of component 20 and panel 16to allow repair of the component part. Third releasable connection 148separates tether 12 from clip 14. Third releasable connection 148 isdisconnected by either applying sufficient force in a direction oppositeto the insertion direction or by manual deflection of deflectable tab 88which allows clip 14 to be slidably disengaged past the end ofengagement member 69. The fourth releasable connection 149 is thestrongest connection and is generally intended to be a permanentconnection, because it may not be readily accessible after installation,and therefore requires manual deflection of the deflectable wings 104,126, and 128 prior to removal of clip 14 from panel 16.

Material for each of the tethers 12 and 200 is preferably a polymericmaterial and in one preferred embodiment is a nylon 6,6 material such asZytel® ST801AHS made by DuPont. According to one preferred embodiment,material for clip 14 is a spring steel material conforming to SAE 1050.

Fastener assemblies of the present invention offer several advantages.By providing multiple releasable connections, each having an individualjoint strength which can be configured in ascending or sequential order,events such as an airbag deployment can be accommodated while preventingcomponent parts such as trim panels from completely separating from thevehicle body panel. Movement of the trim panels may be controlled duringairbag deployment through the use of a tether having at least onefrangible strand in parallel with a non-frangible strand.

The description provided is merely exemplary in nature and, thus,variations are intended to be within the scope of the disclosure. Forexample, as few as two opposed deflectable wings can be used, or agreater number than three deflectable wings can be used for clip 14.Flexible element 24 can be created as a separate part and connectedbetween connector 30 and engagement member 69, which allows connector 30and engagement member 69 to be separately created and/or made usingdifferent materials to differentiate the releasable connectionstrength(s). Clip 14 may be formed from a composite or polymericmaterial. Such variations are not to be regarded as a departure from thespirit and scope of the disclosure.

1. A releasable fastener, comprising: a clip adapted to be coupled to afirst member; and a tether having a first end releasably coupled to theclip, a second end adapted to be coupled to a second member that ismoveable relative to the first member and a flexible member having firstand second strands interconnecting the first and second ends of thetether, wherein the second strand is frangible.
 2. The fastener of claim1 further including third and fourth strands positioned in parallel withthe first and second strands, wherein the second, third and fourthstrands are constructed to sequentially separate under tensile load. 3.The fastener of claim 2 wherein the first, second, third and fourthstrands each have a different length.
 4. The fastener of claim 3 whereinone of the second, third and fourth strands has a locally reducedcross-sectional size.
 5. The fastener of claim 4 wherein one of thesecond, third and fourth strands separates at a location proximate thereduced cross-sectional size.
 6. The fastener of claim 1 wherein one endof the tether includes a pin and the other end includes a receptacle inreceipt of the pin, wherein the pin is released from engagement with thereceptacle prior to separating the second strand.
 7. The fastener ofclaim 6 wherein the clip includes a channel in slidable receipt of thefirst end of the tether.
 8. The fastener of claim 7 wherein the firstend includes a deflectable tab retaining the first end to the clip. 9.The fastener of claim 1 wherein the second strand is adapted to separateupon application of a tensile force provided by the second member movingrelative to the first member.
 10. The fastener of claim 9 wherein thefirst strand is adapted to not separate and restrict movement of thesecond member relative to the first member.
 11. The fastener of claim 1wherein the first strand is adapted to maintain the interconnectionbetween the first and second members after the second strand separates.12. The fastener of claim 1 wherein the second strand is shorter thanthe first strand.
 13. The fastener of claim 1 wherein the second strandis positioned in parallel with the first strand.
 14. The fastener ofclaim 1 wherein the second strand has a recess formed therein to reducea cross-sectional size of the second strand at the recess location. 15.A releasable fastener, comprising: a first connector having a male pin;a second connector flexibly tethered to the first connector, the secondconnector having a receptacle and at least one biasing element operableto releasably engage the male pin; and a clip releasably engageable withthe second connector, wherein the flexible tether includes first andsecond strands, each strand having one end proximate to the firstconnector and an opposite end proximate to the second connector, whereinthe second strand is separable under a predetermined tensile load, thefirst strand remaining interconnecting the first and second connectorswhen subject to the predetermined tensile load.
 16. The fastener ofclaim 15 wherein the second strand is positioned in parallel with thefirst strand.
 17. The fastener of claim 16 wherein the clip furthercomprises a plurality of deflectable wings.
 18. The fastener of claim 17wherein the plurality of deflectable wings comprises a first, a secondand a third deflectable wing, the first deflectable wing opposing boththe second and the third deflectable wings.
 19. The fastener of claim 15further including third and fourth strands positioned in parallel withthe first and second strands, wherein the second, third and fourthstrands are constructed to sequentially separate under the tensile load.20. The fastener of claim 19 wherein the first, second, third and fourthstrands each have a different length.
 21. The fastener of claim 20wherein one of the second, third and fourth strands has a locallyreduced cross-sectional size.
 22. The fastener of claim 15 wherein thesecond connector further comprises a deflectable tab operable toreleasably engage the clip, wherein the deflectable tab is elasticallydeflectable to receive the clip and returns by spring force to retainthe clip.
 23. The fastener of claim 15 wherein the first connectorincludes a hooked end adapted to releasably connect to a first componentof a vehicle and wherein the clip is adapted to releasably connect to asecond component of a vehicle.
 24. A method of manufacturing areleasable fastener, comprising: releasably coupling a first end of atether to a first component; coupling a clip to a second component;releasably coupling a second end of the tether to the clip; releasablycoupling the first end of the tether to the second end of the tether;interconnecting the first tether end and the second tether end with aflexible member having a first strand and a second strand; andseparating the second strand upon relative movement between the firstand second components.
 25. The method of claim 24 maintaining aninterconnection between the first and second components with the firststrand after the second strand separates.